A Regional Resource for Coordinated Intermediate Voltage Transmission Electron Microscopy (300-400 kV, IVEM) and Image Analysis will be established in Philadelphia to serve the mid-Atlantic region of the country. It is expected that sections of embedded cells and tissues up to about 5 micrometers in thickness and even thicker whole mounts of unembedded cells can be examined at these voltages. Images will be recorded either on film or digitized directly for image analysis. The emphasis in the image analysis will be on analysis in three dimensions. Core research will be on development of specimen preparation methods especially suited for study of cells and tissues by electron microscopy in this voltage range, including the development of stains selective for particular cell components. Image analysis core research will be directed toward developing automated data acquisition and efficient user-interactive image manipulation methods for extracting accurate three dimensional information, including morphometric information, from multiple images of structures, either serial micrographs or stereo tilt images. A variety of collaborative research projects is proposed. These projects and their sponsors will interact closely with the core research and the development of Resource capabilities. Letters of interest and intended use of the Resource have been received from users in New York, New Jersey, Pennsylvania, Maryland, and Washington, D.C. Training will be done on-site when users come to the facility, and hands-on workshops are planned for additional training and dissemination of information on the capabilities of the Resource. Further dissemination of results as well as capabilities of the Resource will be done through symposia organized by and/or at the Resource and through publication of research articles and review papers. The overall goal is to bring "state of the art" image processing capabilities into juxtaposition with a powerful tool for examining biological specimens of a wide variety of types and thicknesses in an environment of active and diverse biological research.